Many commercial products have metal surfaces that are treated with one or more surface treatments to create a desired effect, either functional, cosmetic, or both. One example of such a surface treatment is anodizing. Anodizing a metal surface converts a portion of the metal surface into a metal oxide, thereby creating a metal oxide layer, sometimes referred to as an anodic film. Anodic films provide increased corrosion resistance and wear resistance. In addition, anodic films can be used to impart a desired cosmetic effect to the metal surface. For example, pores in the oxide layer formed during anodizing can be filled with dyes to impart a desired color to the surface.
The cosmetic effect of metal surface treatments can be of great importance. In consumer product industries, such as the electronics industry, visual aesthetics can be a deciding factor in a consumer's decision to purchase one product over another. Accordingly, there is a continuing need for new surface treatments or combinations of surface treatments for metal surfaces to create products with new and different visual appearances or cosmetic effects.